The annual physical is the single most common reason that patients seek medical care in the United States. Approximately one third of the 220 million adults in the United States receive an annual physical or preventive exam in any given year. Medicare began reimbursing for the annual wellness exam in 2011. The Affordable Care Act requires all insurers to cover them. Also, many employers include an annual physical exam towards fulfilling employee wellness screening requirements.
Two systematic reviews including both observational and randomized studies concluded that annual physicals due not reduce morbidity or mortality. In fact, they may actually cause harm because abnormal results in asymptomatic individuals are usually false positives.
In 1979, the Canadian Task Force on the Periodic Health Examination recommended that the annual physical exam be abandoned. In 2013, as part of the Choosing Wisely campaign in the United States, the Society of General Internal Medicine recommended eliminating the annual physical exam for asymptomatic adults.
Routine laboratory tests are often ordered regardless of findings elicited from the medical history or physical examination. The annual physical exam often includes a comprehensive metabolic panel, thyroid function tests, lipid analysis, complete blood count, urinalysis and possibly a PSA for men. Ordering tests indiscriminately is costly, counterproductive and may increase patient risk.
Reference ranges for laboratory tests are usually chosen to include 95% of healthy individuals. Therefore, 5% of test results from patients without disease will fall outside the reference range. For example, if hemoglobin levels were measured on100 healthy individuals, 5 would be expected to have abnormal results. Ordering several tests further increases the chances of a healthy person having at least one abnormal result. If two tests are ordered on a healthy individual, the chances of both being normal are 0.95 X 0.95 = 0.90. That means there is a 10% probability that at least one of the results will be abnormal. The chance of at least one test being abnormal increases with the number of tests ordered. When ten tests are ordered, there is a 40% probability of at least one result being abnormal.
Patients can be harmed directly from follow-up of false positive or borderline positive results. Often times, additional confirmatory tests are ordered and patients may be referred to a specialist, who may perform an invasive procedure. Patients can be harmed indirectly when false positive tests divert a physician’s attention from more important patient care issues or unnecessarily result in postponement of a therapeutic procedure. Unnecessary testing contributes to excessive healthcare spending.
Clearly, it is better medical practice to perform only those tests that provide more benefit for the patient than risk. Perhaps it would be wiser to stop ordering laboratory tests for asymptomatic individuals.
Boulware LE etal. Systematic review: the value of the periodic health evaluation. Ann Intern Med 2007;146:289-300.